Minimum recreation space. On any lot that contains a building with three or more dwelling units, a recreation space, distinct and separate from parking areas, service yards and driveways, shall be provided. Such space shall contain not less than 100 square feet for each dwelling unit; moreover, such space shall have good surface drainage, good exposure to sunlight and shall be either surfaced with appropriate materials or in turf. Play space for groups of lots may be consolidated, provided the lots are developed contemporaneously.